Reimplementation of UNION/INTERSECT/EXCEPT. INTERSECT/EXCEPT now meet the

SQL92 semantics, including support for ALL option.  All three can be used
in subqueries and views.  DISTINCT and ORDER BY work now in views, too.
This rewrite fixes many problems with cross-datatype UNIONs and INSERT/SELECT
where the SELECT yields different datatypes than the INSERT needs.  I did
that by making UNION subqueries and SELECT in INSERT be treated like
subselects-in-FROM, thereby allowing an extra level of targetlist where the
datatype conversions can be inserted safely.
INITDB NEEDED!

1 files changed, 21 insertions, 5 deletions

diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 65d35a2977e..06de4be54cb 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: execnodes.h,v 1.50 2000/09/29 18:21:38 tgl Exp $
+ * $Id: execnodes.h,v 1.51 2000/10/05 19:11:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -348,7 +348,6 @@ typedef struct ResultState
  *		whichplan		which plan is being executed
  *		nplans			how many plans are in the list
  *		initialized		array of ExecInitNode() results
- *		rtentries		range table for the current plan
  *		result_relation_info_list  array of each subplan's result relation info
  *		junkFilter_list  array of each subplan's junk filter
  * ----------------
@@ -359,7 +358,6 @@ typedef struct AppendState
 	int			as_whichplan;
 	int			as_nplans;
 	bool	   *as_initialized;
-	List	   *as_rtentries;
 	List	   *as_result_relation_info_list;
 	List	   *as_junkFilter_list;
 } AppendState;
@@ -460,14 +458,12 @@ typedef struct TidScanState
  *		The sub-query will have its own EState, which we save here.
  *		ScanTupleSlot references the current output tuple of the sub-query.
  *
- *		SubQueryDesc	   queryDesc for sub-query
  *		SubEState		   exec state for sub-query
  * ----------------
  */
 typedef struct SubqueryScanState
 {
 	CommonScanState csstate;	/* its first field is NodeTag */
-	struct QueryDesc *sss_SubQueryDesc;
 	EState	   *sss_SubEState;
 } SubqueryScanState;
 
@@ -659,6 +655,26 @@ typedef struct UniqueState
 	MemoryContext tempContext;	/* short-term context for comparisons */
 } UniqueState;
 
+/* ----------------
+ *	 SetOpState information
+ *
+ *		SetOp nodes are used "on top of" sort nodes to discard
+ *		duplicate tuples returned from the sort phase.  These are
+ *		more complex than a simple Unique since we have to count
+ *		how many duplicates to return.
+ * ----------------
+ */
+typedef struct SetOpState
+{
+	CommonState cstate;			/* its first field is NodeTag */
+	FmgrInfo   *eqfunctions;	/* per-field lookup data for equality fns */
+	bool		subplan_done;	/* has subplan returned EOF? */
+	long		numLeft;		/* number of left-input dups of cur group */
+	long		numRight;		/* number of right-input dups of cur group */
+	long		numOutput;		/* number of dups left to output */
+	MemoryContext tempContext;	/* short-term context for comparisons */
+} SetOpState;
+
 
 /* ----------------
  *	 HashState information